Observations on the Ruminal Microorganisms of Isolated and Inoculated Calves

Abstract

Summary A study was made of the microorganisms in the rumen of three calves inoculated with whole rumen contents from a mature cow, and of two calves maintained in the same manner, except that they were not inoculated and were strictly isolated from other ruminants immediately after birth. Data were compared with data previously obtained on normally raised calves. Inoculation of normally raised calves had little effect on the time of establishment of predominant culturable bacteria typical of mature cattle, but had a considerable effect on the age at which ciliate protozoa became established. When calves were isolated from other ruminants to a far greater degree than is likely under practical farm conditions, the bacterial flora was modified from normal through 17 wk. of age, as indicated by bacterial counts, kinds of predominant bacteria cultured, and an apparent effect of inoculation on the flora of these animals after they reached 17 wk. of age. Some groups of typical ruminal bacteria were present. Although the number of animals observed was small, it was apparent that the lack of a normal microbiological population did not have any drastic effect on the animals' feed consumption, growth, or health through an age of 17 wk.